Interlock switch



United States Patent O 3,504,143 INTERLOCK SWITCH James U. Dernehl,l1650 Deerfield Road, Highland Park, lll. 60035 Filed Mar. 24, 1969,Ser. No. 809,538 Int. Cl. H01h 9/26 U.S. Cl. 200-50 6 Claims ABSTRACT OFTHE DISCLOSURE A switch device having a single actuator which when movedin one direction and permitted to be self-restored to its originalposition will effect momentary actuation of a switch blade, and uponextended movement of the actuator in an opposite direction will effect aholding actuation of a complementary switch blade, with the latterswitch blade being restored when the actuator is forcibly returned toits original position.

SUMMARY OF THE INVENTION A switch apparatus having internalcomplementary switching components adapted to be selectively operated bya single actuator. The selection of the switching component to beactuated is determined by the direction of movement of the singleactuator. Normal movement of the actuator in one direction willmomentarily effect actuation of one of the switch components whileextended move ment of the actuator in an opposite direction will actuateand hold the other switch component in an operative circuit makingposition.

These switch apparatuses are known in thetrade as interlocks and theiroperation, as above described, has been usually achieved throughauxiliary mechanical structures which are both expensive and complicatedin construction and operation.

GENERAL DESCRIPTION The invention will be best understood by referenceto the accompanying drawing in which there is shown a preferredembodiment of the invention, and in which:

FIG. Al is a perspective view of the switch apparatus;

FIG. 2 is an internal side elevational View of the switch apparatus inits normal condition;

FIG. 3 is a side elevational view similar to FIG. 2 but showing oneofthe switch units in an actuated condition;

FIG. 4 is a side elevational View similar to FIG. 2 showing the otherswitch component in an actuated condition; and

FIG. 5 is a perspective view of the actuator parts in an explodedrelationship. v

The switch apparatus 10 comprises a case 11 and cornplementary cover 12which together provide internal cavities 13 and 14 aswell as an opening15 in the top wall thereof.

One pair of end walls of the case 11 and cover 12 provide verticallyaligned parallel slots 16 and 17 through which project fixed terminals18 and 19 -with each terminal providing a contact portion positionedwithin the cavities 13 and 14, respectively.

The opposite pair of end walls of the case 11 and cover 12 provide asecond pair of vertically aligned parallel slots 20 and 21 through whicha portion of combination terminal and pivot brackets 22 and 23 project.Each of the combination terminal and pivot brackets 22 and 23 providespivot posts 24 and 25 disposed in a coplanar relationship within thecavities 13 and 14, respectively, as shown in FIGS. 2, 3 and 4.

Each bracket 22 and 23 has associated therewith an over-centeringmechanism by which an associated switch blade is moved relative to thefixed terminals 18 and 19.

Patented Mar. 31, 1970 ICC As seen in the drawings, a switch blade 26has one end pivotally connected to the pivot posts 24 provided by thebracket 22. The blade 26 is pivotally connected to the pivot post 24 bya coil spring 27 that has one end connected to the blade at a pointbeyond the pivot post 24, and its opposite end connected at a remotepoint to the bracket 22. As seen in FIG. 2 in its normal position thecoil spring 27 extends through a plane beneath the point of pivotalconnection between the blade 26 and the pivot post 24, thus the contactbearing end of the blade 26 will normally be held out of contact withterminal 18 and in the position shown wherein its angular end 28 is incontact with a partition wall 29, which separates the cavities 13 and14.

Within the cavity 14, a second switch blade 30 has one end thereofpivotally connected to the pivot post of bracket 23 by means of a coilspring 31 that has one end connected to the switch blade 30, at a pointbeyond the pivot post 25 and its opposite end connected to a remotepoint on the bracket 23. The coil spring 31 normally lies in a planeabove the point of pivotal connection between the blade and the pivotpost 25, so that the blade 30v is in the position shown in FIG. 2 whereits contact bearing end is out of contact with terminal 19 and itsangular end 32 is in engagement with the bottom surface of the partitionwall 29.

Extending through the opening 15 formed in the top wall formed by thecase 11 and cover 12 is a bushing 33. This bushing 33 provides anexternally threaded shank portion 34 which terminates at one end intooppositely extending lateral flanges 35. Carried by the bushing 33 andbeneath the lateral flanges 35 and spaced therefrom are parallellyextending retaining legs 36. When the bushing 33 is mounted in theopening 15 the flanges 35 will engage the top wall surface surroundingthe opening 15 while the parallel legs 36 will engage beneath the wallsurface surrounding the opening 15 and thus connect the bushing 33thereto. An adjustable nut 37 is adapted to be threaded on to the shank34 of the bushing 33 and cooperate with a holding ring 38 alsothreadable upon the shank 34 to connect the switch apparatus 10 to amounting panel which will normally be disposed therebetween.

Freely journaled in the bushing 33 is one elongated end 39 of anactuator 40. This elongated end 39 is normally hollow and contains acoil spring 41, which sits upon a head 42 provided by the actuator 40that is of a size equal to the internal circumference of the elongatedend 39 and about which the lower open end of the member 39 is crimped. j

The actuator includes a circular collar 43 freely journaled in thebearing 33 when each of the parts is mounted within the apparatus asshown in FIGS. 2, 3 and 4. Beneath the circular collar 43, provided bythe actuator 40, are oppositely laterally extending arms 44 which engagethe opposite interior side walls of the cavity 13 and guide the actuatorwhen it is mounted in the apparatus 10. Extending beyond the arms 44 isa depending shank 45 that terminates into a yoke 46. The depending shank`45 of the actuator 40 is adapted to be slidably contained within asuitable cut-out formed in the partition wall 29 as seen. Also formed inthe shank 45 of the actuator 40 is an opening 47 through which the coilspring 27 projects so as to be captured therein when the actuator andswitch components are assembled within the apparatus.

Referring to FIG. 2 there is shown the condition of all of the switchcomponents when the switch apparatus. is in its normal or unactivatedcondition. When the actuator 40 is depressed, by any external force, theyoke 46 which engages the spring 31 will deform the same to a pointbeneath the overcentering line between the blade 30 and the pivot post25, causing the blade to move with a snap action into the position shownin FIG. 3 where it engages the contact provided by the fixed terminal19. As spring 27 is already'below the pivot point between its blade 26and the pivot post 24, increased downward deflection thereof will notpivot the blade 26 out of its normal position as seen in FIGS. 2 and 3.When the external force is removed from the actuator the combinedforcesof the deformed coil springs 27 and 31 will return the actuator toits original position as well as the switch blade 30 so that it is outof contact with the terminal 19. This is the normal functional operationof the switch apparatus. However, in the event that a continuing circuitis desired to be completed through the switch apparatus and not amomentary closing as just described, the actuator end 39 can be pulledin a direction out of the bushing 33 which movement in turn will deformthe coil spring 27 to a point where it will overcenter and move with asnap action the switch blade 26. This position is shown in FIG. 4. Byreason of the fact that the yoke 46 of the actuator 40` does not embracethe spring 31 it will not cause any deformation thereof. The tension ofthe spring 27 when it has been moved into the position shown in FIG. 4will maintain the actuator 40 in this position until it is forciblydepressed in an opposite direction, and all of the switching componentsare returned to their original conidtion as seen in FIG. 2.

By the construction of the actuator 40 as hereinbefore described theexposed end 39 has a lost motion connection to the remaining part of theactuator, which is disposed within the cavity 13. This lost motion isachieved through the internal spring 41 and the loose connection betweenthe end 39 and the head 42 which permits continuous depression of theend 39 inwardly of the bear ing 33 after the internal part of theactuator 40 has actuated the switch blade 30 in the manner hereinbeforedescribed and shown in FIG. 3.

While I have illustrated and described the preferred form ofconstruction for carrying my invention into effect, this is capable ofvariation and modication without departing from the spirit of theinvention. I, therefore, do not wish to be limited to the precisedetails of construction set forth, but desire to avail myself of suchvariations and modifications as come within the scope of the appendedclaims.

Having thus described my invention, what I claim as new and desire toprotect by Letters Patent is:

1. A switch apparatus including a housing having an interior cavitycontaining a pair of overcentering mechanisms, each including a coilspring anda switch blade with the switch blades independently movablewith a snap action in opposite directions to complete a circuittherethrough wherein the improvement comprises:

(a) an actuator carried by the housing and movable through a reciprocallinear path relative to the longitudinal plane of the coil springs andswitch blades,

of said portion of said actuator within the cavity in contact with theother of the coil springs,

(d) said means deforming the coil springs in one direction out of theirlongitudinal plane to independently pivot one of the switch blades insaid one direction when said actuator is depressed out of its normalposition and to deform one of the coil springs independentlyof the otherof the coil springs to independently pivot the other of the switchblades in an opposite direction when said actuatoris moved out of itsnormal position through the housing in said opposite direction.

2. A switch apparatus as defined by claim 1 wherein said means formed insaid portion of said actuator within the cavity of the housing consistsof an opening formed through said actuator in the longitudinal plane ofone of the coil springs, and through which the one coil spring extendsand is captured so as to be deformed out of its longitudinal plane bymovement of said actuator in either direction transversely with respectthereto.

3. A switch apparatus as defined by claim 1 wherein said means providedon one end of said portion of said actuator within the' cavity comprisesa yoke embracing the spring inv one direction to pivot one of the switchblades in said one direction when said actuator is moved in said onedirection through the cavity of the housing.

(b) means for mounting said actuator on the housing v 4. A switchapparatus as defined by claim 3 wherein said means formed in saidportion of said actuator within the cavity of the housing consists of anopening formed through said actuator in the longitudinal plane of theother coil spring and through which the said other coil spring extendsand is captured so as to be deformed out of its longitudinal plane bymovement of said actuator in either direction transversely with respectthereto.

5. The switch apparatus of claim 1 further defined by having the coilsprings of the overcentering mechanisms disposed in vertical alignmentand extending transversely to said actuator and having suiiicienttension developed therein when deformed by said actuator when it ismoved out of its normal position in one direction by an external forceto reciprocally move said actuator in an opposite direction to restoreit to its normal position when the external force is removed therefrom.

6. A switch apparatus of claim 4 further defined by having the coilsprings of the overcentering mechanisms disposed in vertical alignmentand extending transversely to said actuator and having sufficienttension developed therein when deformed by said actuator when it ismoved out of its normal position in one direction by an external forceto reciprocally move said actuator in an opposite direction to restoreit to its normal position when the external force is removed therefrom.

References Cited UNITED STATES PATENTS 2,519,297 8/ 1950 Stump et al200-76 XR ROBERT S. MACON, Primary Examiner M. GINSBURG, AssistantExaminer U.S. Cl. XR. 200-76

